﻿using UnityEngine;
using UnityEngine.UI;
using System.Collections;

namespace MoreMountains.Tools
{
	/// <summary>
	/// Add this class to a gameObject with a Text component and it'll feed it the number of FPS in real time.
	/// </summary>
	[RequireComponent(typeof(Text))]
	[AddComponentMenu("More Mountains/Tools/Performance/MMFPSCounter")]
	public class MMFPSCounter : MonoBehaviour
	{
		public enum Modes { Instant, MovingAverage, InstantAndMovingAverage }
		
		/// the frequency at which the FPS counter should update (in seconds)
		public float UpdateInterval = 0.3f;
		/// if this is true, this counter will display a moving average of the framerate, not its instant framerate 
		public Modes Mode = Modes.Instant;

		protected float _framesAccumulated = 0f;
		protected float _framesDrawnInTheInterval = 0f;
		protected float _timeLeft ;
		protected Text _text;
		protected int _currentFPS;
		protected int _totalFrames = 0;
		protected int _average;

		static string[] _stringsFrom00To300 = {
			"00", "01", "02", "03", "04", "05", "06", "07", "08", "09",
			"10", "11", "12", "13", "14", "15", "16", "17", "18", "19",
			"20", "21", "22", "23", "24", "25", "26", "27", "28", "29",
			"30", "31", "32", "33", "34", "35", "36", "37", "38", "39",
			"40", "41", "42", "43", "44", "45", "46", "47", "48", "49",
			"50", "51", "52", "53", "54", "55", "56", "57", "58", "59",
			"60", "61", "62", "63", "64", "65", "66", "67", "68", "69",
			"70", "71", "72", "73", "74", "75", "76", "77", "78", "79",
			"80", "81", "82", "83", "84", "85", "86", "87", "88", "89",
			"90", "91", "92", "93", "94", "95", "96", "97", "98", "99",
			"100", "101", "102", "103", "104", "105", "106", "107", "108", "109",
			"110", "111", "112", "113", "114", "115", "116", "117", "118", "119",
			"120", "121", "122", "123", "124", "125", "126", "127", "128", "129",
			"130", "131", "132", "133", "134", "135", "136", "137", "138", "139",
			"140", "141", "142", "143", "144", "145", "146", "147", "148", "149",
			"150", "151", "152", "153", "154", "155", "156", "157", "158", "159",
			"160", "161", "162", "163", "164", "165", "166", "167", "168", "169",
			"170", "171", "172", "173", "174", "175", "176", "177", "178", "179",
			"180", "181", "182", "183", "184", "185", "186", "187", "188", "189",
			"190", "191", "192", "193", "194", "195", "196", "197", "198", "199",
			"200", "201", "202", "203", "204", "205", "206", "207", "208", "209",
			"210", "211", "212", "213", "214", "215", "216", "217", "218", "219",
			"220", "221", "222", "223", "224", "225", "226", "227", "228", "229",
			"230", "231", "232", "233", "234", "235", "236", "237", "238", "239",
			"240", "241", "242", "243", "244", "245", "246", "247", "248", "249",
			"250", "251", "252", "253", "254", "255", "256", "257", "258", "259",
			"260", "261", "262", "263", "264", "265", "266", "267", "268", "269",
			"270", "271", "272", "273", "274", "275", "276", "277", "278", "279",
			"280", "281", "282", "283", "284", "285", "286", "287", "288", "289",
			"290", "291", "292", "293", "294", "295", "296", "297", "298", "299",
			"300"
		};

		/// <summary>
		/// On Start(), we get the Text component and initialize our counter
		/// </summary>
		protected virtual void Start()
		{
			if(GetComponent<Text>()==null)
			{
				Debug.LogWarning ("FPSCounter requires a GUIText component.");
				return;
			}
			_text = GetComponent<Text>();
			_timeLeft = UpdateInterval;
		}

		/// <summary>
		/// On Update, we increment our various counters, and if we've reached our UpdateInterval, we update our FPS counter
		/// with the number of frames displayed since the last counter update
		/// </summary>
		protected virtual void Update()
		{
			_framesDrawnInTheInterval++;
			_framesAccumulated = _framesAccumulated + Time.timeScale/Time.deltaTime;
			_timeLeft = _timeLeft - Time.deltaTime;

			if( _timeLeft <= 0.0 )
			{
				_currentFPS = (int)Mathf.Clamp (_framesAccumulated / _framesDrawnInTheInterval, 0, 300);
				_framesDrawnInTheInterval = 0;
				_framesAccumulated = 0f;
				_timeLeft = UpdateInterval;
				_totalFrames++;
				_average += (_currentFPS - _average) / _totalFrames;
		        
				if (_currentFPS >=0 && _currentFPS <= 300)
				{
					switch (Mode)
					{
						case Modes.Instant:
							_text.text = _stringsFrom00To300[_currentFPS];
							break;
						case Modes.MovingAverage:
							_text.text = _stringsFrom00To300[_average];
							break;
						case Modes.InstantAndMovingAverage:
							_text.text = _stringsFrom00To300[_currentFPS] + " / " + _stringsFrom00To300[_average]; 
							break;
					}
			        	
				}
			}
		}
	}
}